Display apparatuses have been widely used. For example, there are display screens for displaying pictures in such places as shopping malls, factories, schools, buses, etc. Display apparatuses can display such information as text, pictures, video, etc. A considerable amount of them are mounted in the open air or in public places. Since the display apparatuses are distributed geographically, it is difficult and inefficient to monitor their faults timely and accurately. In addition, a person who checks whether a display apparatus has a fault or analyzes the fault is usually not a professional maintenance engineer and thus cannot accurately determine the fault type. Furthermore, a conventional display apparatus feeds back a small amount of information to a maintainer. This increases the workload of the maintainer and meanwhile makes it difficult to ensure the efficiency and accuracy of the maintenance operation.